This invention pertains to the art of assembly systems using robots.
The assembly of industrial products, manufactured by low volume batch production methods, is one of the most costly processes in industry. Some degree of automation would be a way to reduce the cost of assembly. However, because of the low volume involved in the batch production method (usually 10 to 2,000 products in a batch), conventional programmable automatic assembly systems for these products are needed but often cannot be economically justified. A programmable automatic assembly system would imply the inclusion therein of what is sometimes called servo-controlled robots, which in a published article entitled "Basics of Robotics", by Williams R. Tanner are characterized in part as relatively complex, more expensive, more involved to maintain, and less reliable than non-servo robots.
In that same article, Mr. Tanner discusses non-servo robots as follows: "Non-servo robots are often referred to as `end point,` `pick and place,` `bang-bang` or `limited sequence` robots. However, these terms imply limited capability and restricted applicability, which is not necessarily the case. The term "non-servo" is more descriptive and less restrictive than the others used." He also states that common characteristics of non-servo robots include: "relatively high speed is possible, due to the generally smaller size of the manipulator." "Repeatability to within 0.25 mm. (0.010 in.) is attainable on the smaller units." "These robots are relatively low in cost; simple to operate, program and maintain; and are highly reliable." "These robots have limited flexibility in terms of program capacity and positioning capability."
The term "non-servo robot" is used in this application in the same sense as in the noted article and to distinguish it from the servo-controlled robot.
The aim of the invention is to provide a versatile, programmable, high speed assembly system which uses the highly reliable, highly accurate, and low cost non-servo robot as a part thereof.